The 7th Doctor

When the TARDIS was attacked by the Rani, the Sixth Doctor was injured and forced to regenerate. After a brief period of post-regenerative confusion and amnesia (chemically induced by the Rani), the Seventh Doctor thwarted the Rani's plans, and rejoined his companion Mel for whimsical adventures in an odd tower block and a Welsh holiday camp in the 1950s

On the planet Svartos, Mel decided to leave the Doctor's company for that of intergalactic rogue Sabalom Glitz. Also at this time, the Doctor was joined by time-stranded teenager Ace. Although he did not mention it at the time, the Doctor soon recognised that an old enemy from a past adventure, the ancient entity known as Fenric, was responsible for the Time Storm which transported Ace from 1980s Perivale to Svartos in the distant future. Growing more secretive and driven from this point on, the Doctor took Ace under his wing and began teaching her about the universe, all the while keeping an eye out for Fenric's plot. The Doctor began taking a more scheming and proactive approach to defeating evil, using the Gallifreyan stellar manipulator named the Hand of Omega as part of an elaborate trap for the Daleks which resulted in the destruction of their home planet, Skaro. Soon afterwards, the Doctor used a similar tactic and another Time Lord relic to destroy a Cyberman fleet. He engineered the fall of the oppressive government of a future human colony in a single night and encountered the Gods of Ragnarok at a circus on the planet Segonax, whom he had apparently fought throughout time. Later, he was reunited with his old friend, Brigadier Lethbridge-Stewart while battling the forces of an alternate dimension on Earth.

The Seventh Doctor's manipulations were not reserved for his enemies. With the goal of helping Ace confront her past, he took her to a Victorian house in her home town of Perivale in 1883 which she had burned down in 1983. Eventually, the Doctor confronted and defeated Fenric at a British naval base during World War II, revealing Fenric's part in Ace's history. The Doctor continued to act as Ace's mentor, returning her to Perivale; however, she chose to continue travelling with him. The circumstances of her parting from the Doctor were not shown on television.

Near the end of his incarnation, the Seventh Doctor was given the responsibility of transporting the remains of his former enemy the Master from Skaro to Gallifrey. This proved to be a huge mistake: despite having a limited physical form, the Master was able to take control of the Doctor's TARDIS and cause it to land in 1999 San Francisco, where the Doctor was shot in the middle of a gang shoot-out. He was taken to a hospital, where surgeons removed the bullets but mistook the Doctor's double heartbeat for fibrillation; their attempt to save his life instead caused the Doctor to "die" with one last shocking scream. Perhaps due to the anesthesia, the Doctor did not regenerate immediately after death (unlike all previous occasions); he finally did so several hours later, while lying in the hospital's morgue.as the 8th doctor played by David Schwimmer